Python：在del中使用for循环 [英] Python: Using del in for loops

问题描述

当我意识到del似乎不起作用时，我正在遍历带有for循环的列表。我认为这是因为我代表的是for循环的对象，而del只是删除该对象而不是引用。

I was iterating through a list with a for loop, when I realized del seemed to not work. I assume this is because i is representing an object of the for loop and the del is simply deleting that object and not the reference.

但是，我确定我已经

alist = [6,8,3,4,5]  

for i in alist:  
    if i == 8:  
        del i  

在我的代码中实际上是一个字符串列表，但结果是相同的：即使满足条件，删除i也无效。

In my code its actually a list of strings, but the result is the same: even though the if conditional is satisfied, deleting i has no effect.

有没有办法我可以用这种方式删除数字或字符串？我在做错什么吗？

Is there a way I can delete a number or string in this way? Am I doing something wrong?

谢谢。

推荐答案

您的想法关于为什么您看到这种行为是正确的。因此，我将不再赘述。

Your idea as to why you are seeing that behavior is correct. Hence, I won't go over that.

要执行您想要的操作，请使用列表理解可以过滤列表：

To do what you want, use a list comprehension to filter the list:

>>> alist = [6,8,3,4,5]
>>> [x for x in alist if x != 8]
[6, 3, 4, 5]
>>> alist = [6,8,8,3,4,5]
>>> [x for x in alist if x != 8]
[6, 3, 4, 5]
>>>

这种方法也比for循环更有效。

This approach is also a lot more efficient than a for-loop.

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